A semiconductor device can be tested in a stress test referred to as a burn-in test using a printed circuit board or burn-in board that is designed to receive the semiconductor device. The burn-in board includes an array of sockets and interconnecting printed circuit traces or electrical leads. The burn-in board can be plugged into edge connectors in a rack in an oven after being loaded with the semiconductor devices to be tested. The edge connectors electrically connect the semiconductor devices and sockets to test signal generating circuits proximate the oven. The oven is then closed to seal the semiconductor devices in the oven while the ambient air in the oven is heated and the semiconductor devices are operated by the test signal generator circuits. Unreliable semiconductor devices fail and the rest of the semiconductor devices can be further tested and eventually sold.
Typical sockets used for burn-in testing include a base member formed of electrically insulative material in which an electrical contact element is mounted for each lead of the semiconductor device to be tested. The contact elements can be arranged in a selected pattern relative to a semiconductor device provided in the base and have movable contact portions adapted to move into and out of electrical engagement with respective leads of the semiconductor device. Typically, a cover member can be movably mounted on the base and can be provided with a structure that allows the contact elements to move away from a semiconductor device mounting seat when the cover member is in an open position. This permits placement of a semiconductor device in and removal of the semiconductor device from the socket. When the cover member is moved to a closed position the contact elements are caused to move into electrical engagement with the respective leads of the semiconductor device.
Semiconductor devices can be become heated during the burn-in test to potentially undesirable or excessive temperatures. Excessive temperatures may affect the performance of the circuit and cause permanent degradation of the semiconductor device. It is, therefore, desirable to hold the temperature of the semiconductor device at a relatively constant temperature throughout the burn-in test.
The traditional method for cooling semiconductor devices during burn-in that has been through convection heat transfer. Using this method, heat is dissipated from the semiconductor device through the outer surfaces of the device into still or moving air. As the integration level (i.e., the number of transistors per device) of semiconductor devices increases, or the power requirements, or the operating speed of these semiconductor devices increases, the amount of heat generated by these semiconductor devices increases to a point where conventional convection solutions are inadequate. This poses a particular problem when testing semiconductor devices housed within packages having a low thermal mass. If the semiconductor device is not adequately cooled during the test, and is permitted to rise significantly above a designated test temperature, the semiconductor device may suffer permanent degradation. In such instances, the semiconductor device must be discarded.